Vatican City uses Italian in its official documents and as its main working language. However, many other languages are also used by institutions situaed within the state, such as the Holy See and the Swiss Guard, as well as personally by its diverse population.
Roman Empire, Latin was the main language spoken in the area corresponding to the present Vatican City. The subsequent Papal States also used Latin for official purposes during the first centuries of their existence, but various Italian languages were spoken, such a standard Italian (based on Tuscan). In 1870 the area became part of the Kingdom of Italy, whose official language was Italian.
In 1929 the Lateran Treaty established Vatican City as an independent state. The Fundamental Law of Vatican City State does not establish an official language, but its laws are published in Italian in a supplement to the Acta Apostolicae Sedis (official gazette of the Holy See), which is mainly in Latin.
Since the state came into existence only in 1929, most of the buildings situated within it predated it by centuries. Inscriptions can be found in them mainly in Latin, but also in Italian, Greek, French and German.
Many languages are spoken within the state, as its inhabitants come from many countries. Italian is the lingua franca of the Vatican and replaced Latin as the official language of the Synod of Bishops in 2014. The Holy See, the entity with authority over the state (yet legally distinct), uses Latin as its official language, Italian as its main working language, and French as its main diplomatic language. In the Swiss Guard, Swiss German is the language used for giving commands, but the individual guards take their oath of loyalty in their own languages: German, French, Italian or Romansh.
The official website of the Holy See is primarily in Italian, with versions in English, French, German, Portuguese and Spanish, and partial versions in Arabic, Chinese and Latin. Some content is also available in many other languages, such as Albanian, Belarusian, Croatian, Czech, Dutch, Hebrew, Hungarian, Indonesian, Japanese, Korean, Lithuanian, Maltese, Polish, Russian, Slovak, Slovene, Swahili and Ukrainian.
The Holy See's newspaper L'Osservatore Romano is published in Italian, English, French, German, Polish, Portuguese and Spanish. The Vatican News website is available in many languages: Albanian, Amharic, Arabic, Armenian, Belarusian, Bulgarian, Chinese, Croatian, Czech, English, French, German, Italian, Japanese, Korean, Latvian, Lithuanian, Hindi, Hungarian, Malayalam, Macedonian, Polish, Portuguese, Romanian, Russian, Slovak, Slovene, Spanish, Swahili, Swedish, Tamil, Tigrinya, Ukrainian and Vietnamese.